Clostridium is a genus of Gram-positive bacteria, which contains around 100 species including common free-living bacteria, as well as important pathogens. Clostridium endospores have a distinct bowling pin or bottle shape, distinguishing them from other bacterial endospores, which are usually ovoid in shape. Clostridium species inhabit soils and the intestinal tract of animals, including humans. In general, the treatment of clostridial infection is high-dose penicillin G, to which the organism has remained susceptible.